26.2 Performance Schema Build Configuration

The Performance Schema is mandatory and always compiled in. It is
possible to exclude certain parts of the Performance Schema
instrumentation. For example, to exclude stage and statement
instrumentation, do this:

If you install MySQL over a previous installation that was
configured without the Performance Schema (or with an older
version of the Performance Schema that may not have all the
current tables), run mysql_upgrade after
starting the server to ensure that the
performance_schema database exists with all
current tables. Then restart the server. One indication that you
need to do this is the presence of messages such as the following
in the error log:

Because the Performance Schema is configured into the server at
build time, a row for
PERFORMANCE_SCHEMA appears in the
output from SHOW ENGINES. This
means that the Performance Schema is available, not that it is
enabled. To enable it, you must do so at server startup, as
described in the next section.